I wouldn't say it's immature and uneducated whining at all.
That fact is that football is an incredibly divisive sport anyway. What you might consider to be a foul or a great goal, won't be the same as someone else.
If you were to ask 100 people "what is the most important thing in a football game?" you'd get so many different answers - realism, playing as my favourite players, licenses, 30 yard screamers, amazing face scans, physics, skill moves, tactical options, etc, etc. Not everyone's idea of fun is listening to ref blow his whistle every 5 seconds, and you'll find just as many people who love the fanciful things like beating 5 players with Ronaldo, as you do people who love gameplay as close to a sim as possible. I remember finding it hilarious listening to fans a few years ago talk about net physics like they're the most important thing in the world.
I totally agree with you that players should have a choice, and be able to set the game up to play by the rules that they want, but that only applies to offline. You still need to pick a setting that will apply to everyone when playing online matches.
Personally, I have no problem with the number of fouls in the game, but I don't like the inconsistency between what players and the AI can get away with. I'd be happy to make the ref a bit more strict with the AI, and a bit more lenient with the player.